Synthesis and in vitro antibacterial activity of some N-(5-aryl-1,3,4-thiadiazole-2-yl)piperazinyl quinolone derivatives

Synthesis and Antibacterial Activity of Nitroaryl Thiadiazole‐Levofloxacin Hybrids

“…Reaction of N-desmethyl levofloxacin 5 with 2-chloro-5-(nitroaryl)-1,3,4-thiadiazole 6a -f in ethanol in the presence of NaHCO 3 at reflux temperature gave compounds 4a -f [5]. The intermediate N-desmethyl levofloxacin 5 was prepared according to the known method [8], by the reaction of piperazine with ( -)-9,10-difluoro-2,3-dihydro-3-methyl-7-oxo-7H-pyrido[1,2,3-de] [1,4]benzoxazine-6-carboxylic acid.…”

“…Furthermore, it has been proposed that for Gram-positive organisms, increasing molecular mass and bulkiness of a substituent at the C-7 position is not a barrier to penetration [4]. Based on these considerations, several types of hybrids including quinolonenitrofuran [5], quinolone-nitrothiophene [6], and quinolone-nitroimidazole [7] hybrids 3 have been synthesized and evaluated by us. Preliminary data indicated that these quinolone-nitroheterocycle hybrids 3 have a potent activity against Gram-positive organisms with enhanced anti-staphylococcal activity compared with the parent fluoroquinolones (ciprofloxacin, norfloxacin, and enoxacin).…”

DFT Investigation of Chelation of Divalent Cations by Some 4-Benzylidenamino-4,5-Dihydro-1H-1,2,4-Triazol-5-One Derivatives

“…In general, 1,2,4 triazole derivatives are biologically versatile compounds displaying a variety of biological effects which include anti-imflammatory [1], antimycobacterial [2][3], antifugal [4], antibacterial [5][6] and antiviral activities [3]. The 4-benzylidenamino-4,5-dihydro-1H-1,2,4-triazol-5-one derivatives obtained through the reaction [7] of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones with 3,4 dihydroxy benzaldehyde, possess various biological properties such as anticonvulsant [7], antifungal [8][9], antituberculosis [10] and antiproliferative [11] activities. In addition, 4,5-dihydro-1H-1,2,4-triazol-5-one derivatives which exhibit important pharmacological activities such as antivirius [12] and antioxidant [13][14] have found wide use in medicinal chemistry as common structures.…”

Synthesis and Biological Activity of Novel Pinanyl Thiazole Derivatives

“…在医药领域, 噻唑类化合物显示 出巨大的开发和应用价值, 如雷夫康(抗真菌剂) [12] 、硝 唑尼特(寄生虫祛除剂) [13] 、美洛昔康(抗炎剂) [14] 等药物 已实现工业化生产. 在农药领域, 噻唑类化合物以其低 毒的杀虫效果、高效的植物生长调节作用 [15,16] 得到广泛 应用 [17～19] , 如噻虫嗪 [20] 作为杀虫剂、氟噻乙草酯 [21,22] 作为除草剂取得了较好的使用率. β-蒎烯是松节油的主 要成分之一, 目前主要用于合成香料方面, 而将噻唑环 引入蒎烯类化合物中的文献报道较少, 同时 β-蒎烯本身 具有抑制真菌作用 [23] , 并且对许多害虫均有较强的杀 灭作用, 是常用的粮食除虫剂 [24] .…”